RU2139779C1 - Installation for laser treatment of brittle materials - Google Patents

Abstract

FIELD: laser engineering, applicable for shaped cutting of simple glass, glass ceramic, various kinds of ceramics, etc. SUBSTANCE: the installation comprises a mechanism for action on the surface of the treated plate on the inactive side. The mechanism working member may be made in the form of a movable ball. The mechanism proper has a two-coordinate movement system. Movements of the mechanism and optico-focusing system in the process of installation operation are synchronous, which provides for an effective cutting of material. The shaker, incorporated in the mechanism, also enhances the efficiency of cutting. The value of the force of action of the working member on the surface of treated material is determined proceeding from the process conditions of treatment - material, its thickness, radiating power, etc. EFFECT: higher efficiency. 3 cl, 3 dwg

Description

 The present invention relates to the field of laser processing of sheet materials, namely to figured cutting of flat sheets using laser radiation, and can be used for the manufacture of parts of various configurations from brittle materials - glass, ceramics, etc. wide nomenclature in mechanical engineering, construction, electrical engineering, aircraft and automotive.

 It is known that the traditional methods of processing brittle materials used in industry are largely subjective, difficult to automate, and require widespread use of manual labor [1].

It is known that the processing of brittle materials is possible using laser radiation - thermal cracking [2]. The process is as follows. Using laser radiation, the surface of the material being processed is exposed. In this case, a local heating of the site of exposure to a temperature occurs, exceeding the limit of heat resistance, when the induced thermal voltages exceed the tensile strength. Under certain conditions, the crack that appears follows a laser beam at a certain distance along the path described by it. The length L of the delay in the beginning of the crack from the surface irradiation point moving with speed V is determined by the time of heat diffusion across the plate [3]
L = Vh ² / 4a.

 The main disadvantage of thermal cracking is the delay in the motion of an emerging crack beyond the path of a moving beam. This leads to inaccuracy in the repetition of the crack of the laser beam path and, accordingly, to the defect of the part. Often, an emerging crack goes away from the path of the laser beam.

 A known installation for laser processing of brittle materials containing a technological laser, a moving system with an optical focusing head placed on it and a support for placing and securing a processed sheet on it (see US 4467.168 B 23 K 27/00, 08.21.84) .

 Installation works as follows. A sheet of glass of a given thickness is oriented on a support and a laser beam is directed at it, which is focused on the surface of the sheet, heating it in the focus area. A gas stream is directed into the heating zone, which removes vapors and splashes of glass. This installation has the same disadvantages as indicated above.

 The problem solved by this invention is to improve the quality of processing of brittle materials, reducing the percentage of rejects.

 The above problem is solved due to the fact that in the installation for laser processing of brittle materials containing a technological laser, a moving system with an optical focusing head placed on it and a support for placing and securing a processed sheet on it, the support for the processed sheet is made in the form of a frame, from the side of the sheet to be processed, the opposite side, on which the optical focusing head acts, a two-coordinate system for moving the mechanism of action on the surface is placed on the frame one hundred. The mechanism has a working element, a system for moving the working element in the direction perpendicular to the surface of the processed sheet, and a vibration device. The mechanism of action on the surface of the sheet moves synchronously with the optical focusing head. The working element can be made in the form of a movable ball.

 Using this mechanism allows exposure to a certain pressure on the processed sheet at the site of exposure to the given sheet of laser radiation.

 This eliminates the delay of the crack beyond the path of the laser radiation, and the possibility of spoilage is practically eliminated. The accuracy of cutting parts increases. Vibration device allows for more effective impact on the surface of the processed sheet.

 The design of the installation is as follows (Fig. 1, 2). A technological laser 2 is located near the frame 1. The sheet 3 intended for processing is fixed in the frame in a vertical position. On the opposite side is a two-coordinate system of movement 6 of the mechanism of action on the surface of the sheet.

 The mechanism itself is as follows. The working element 7 directly affects the surface of the sheet, it is pressed with a certain force by the movement system of the working element 8, at the end of which a vibration device 9 is fixed.

 Installation works as follows. According to the control signals of the control system (not shown in FIG.), The radiation generated by the process laser 2 (dash-dot line) is sent to the opto-focusing head 5, where it is focused and directed directly to the processed sheet 3. The optical-focusing head moves through the workspace by the system movements 4. On the back side of the sheet 1 fixed in the frame, synchronously with the system 4, the movement system 6 of the mechanism for influencing the surface of the sheet is moved. The working element 7 constantly presses on the sheet with a force F (Fig. 3). The magnitude of the force F is determined from technological considerations and is regulated by the displacement system 8. For more efficient implementation of the cutting process (for example, when cutting large thicknesses), together with the pressure, which is constant for a given material and given thickness, a vibration load is used by the vibration device.

 The pressure force F creates internal stresses at the site of exposure to the laser radiation, which together with the laser radiation also lead to the destruction of the material. The vibration device creates alternating loads at the impact site, which also contributes to the effective destruction of the material. The working element can be structurally performed in various ways, which does not affect the tasks solved by the invention.

List of references
1. Technological lasers: Reference: In 2 vols. T. 1: Calculation, design and operation / G.A.Abilsiitov, BCGolubev, V.G. Under the total. ed. G.A.Abilsiitova. -M .: Engineering, 1991, p. 341.

 2. Technological lasers: Reference: In 2 vols. T. 1: Calculation, design and operation / G.A.Abilsiitov, B.C. Golubev, V.G. Gontar and others; Under the total. ed. G.A.Abilsiitova. -M.: Mechanical Engineering, 1991, p. 343.

 3. Machulka G.A. Laser processing of glass. -M .: Soviet Radio, 1979, p. 136.

Claims (3)

 1. Installation for laser processing of brittle materials, containing a technological laser, a control system, a radiation transportation system, a moving system with an optical focusing head placed on it and a frame for placing and securing a processed sheet on it, characterized in that the installation is equipped with a mechanism for influencing the surface of the sheet, including the working element and the system of its movement in the direction perpendicular to the surface of the processed sheet, mounted coaxially with the optical focusing head minutes and capable of acting on the surface opposite the working surface of the sheet.  2. Installation according to claim 1, characterized in that the mechanism of action on the surface of the sheet includes a vibration device.  3. Installation according to claim 1, characterized in that the working element is made in the form of a movable ball.

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